Alzheimer's disease (AD) is caused by multiple genetic and/or environmental
etiologies. Because differences in the genetically determined pathogenesis
may cause differences in the phenotype, we examined age at onset and age a
t death in 90 subjects with dominantly inherited AD due to different mutati
ons (amyloid precursor protein, presenilin-1, and presenilin-2 genes). We f
ound that among patients with dominantly inherited AD, genetic factors infl
uence both age at onset and age at death.